FSH and LH levels, what day?

Lo
Hi, can anyone advise me. I booked in for some bloods to be taken tomorrow but my AF is slightly later than I thought it would be. Tomorrow will be the 2nd day of AF. Is it ok to have the levels tested on day 2 or should I ring up to re book for a day or 2 later? I can't remember if it's a cd2-5 or 3-5 test..... thanks x